Pressure actuated valves and methods of use

Abstract

The present invention provides unique pressure actuated valves and related methods that may be used in applications where a plurality of fluid emission devices are provided on a plurality of lines containing fluid under pressure, in order to prevent fluid from escaping from the fluid emission devices until a consistent threshold or predetermined level of fluid pressure is obtained in the lines, without causing significant water pressure and/or flow loss through the valves. Valves of the present invention include a housing having an upper body and a lower body that may be coupled together to form an inner chamber, the lower body having an inlet in communication with a source of fluid under pressure, the upper body having an outlet in communication with a fluid emission device. A hollow movable fluid transmission piston is provided in the chamber for communicating between the inlet and outlet. The chamber formed between the upper and lower bodies may be provided with cup seals at opposite ends of the chamber to reduce friction and prevent fluid from entering therein, and a side air vent. A wider lower end of the piston is urged toward the lower housing body using a biasing mechanism, which pushes an O-ring at the lower end against a stop to prevent fluid from entering into the hollow center of the piston. When fluid with a sufficient pressure is provided from the source, it pushes the O-ring away from the stop and against the urging of the biasing member, allowing fluid to flow around the stop, through the center of the piston, and out through the upper body into the fluid emission device. The vent in the chamber allows air inside the chamber (surrounding the biasing mechanism) to escape so that there is no added air pressure within the chamber to be overcome by the fluid pressure.

1 - 10 . (canceled) 
     
     
         11 . A valve for an irrigation system comprising:
 a) a housing comprising two parts which define an internal chamber when coupled together, a first of said parts of said housing having an inlet in fluid communication with an irrigation line, and a second of said parts having an outlet in fluid communication with a sprinkler head, said inlet further comprising a stop, and said chamber having a central axis therethrough;   b) a hollow piston inside said chamber, said piston having a fluid passageway therethrough that is aligned with the central axis of said chamber, said piston having an inlet to said passageway adjacent to the inlet of said chamber, an outlet from said passageway adjacent to the outlet of said chamber, and a seal at said piston inlet operable to provide watertight sealing against said stop;   c) a biasing member in said chamber, said biasing member being operable to bias said seal against said stop until overcome by water in said inlet end reaching or exceeding a threshold pressure;   d) a first sealing member operable to provide a watertight seal between said piston and an interior surface of said first part of said housing;   e) a second sealing member operable to provide a watertight seal between said piston and an interior surface of said second part of said housing; and   f) at least one air vent in a wall of said chamber.   
     
     
         12 . The valve of  claim 11  wherein the seal at said piston inlet is an O-ring, said first sealing member is a cup seal, and said second sealing member is a cup seal. 
     
     
         13 . A method of using irrigation start valves comprising the steps of:
 a. providing an irrigation line having a plurality of openings thereon;   b. installing a pressure actuated valve at each such opening, each of said pressure actuated valves comprising
 a housing comprising two parts which define an internal chamber when coupled together, a first of said parts of said housing having an inlet in fluid communication with said irrigation line, and a second of said parts having an outlet in fluid communication with a sprinkler head, said inlet further comprising a stop, and said chamber having a central axis therethrough; 
 a hollow piston traversing said chamber, said piston having a fluid passageway therethrough that is aligned with the central axis of said chamber, said piston having an inlet to said passageway adjacent to the inlet of said chamber, an outlet from said passageway adjacent to the outlet of said chamber, said chamber being sealed at said chamber inlet by a first sealing member, and sealed at said chamber outlet by a second sealing member, wherein said piston is biased against said stop by a biasing member until overcome by water in said inlet reaching or exceeding a threshold water pressure; 
   C. engaging a plurality of sprinkler heads with the outlets of said plurality of pressure actuated valves; and   d. providing water under pressure to said irrigation line such that when the threshold water pressure is reached, the piston is separated from the stop on each of the plurality of valves.   
     
     
         14 . The method of  claim 13  wherein an O-ring seal is provided on each piston that is urged against each stop by each biasing member. 
     
     
         15 . The method of  claim 13  wherein, each first sealing member is a cup seal, and each second sealing member is a cup seal. 
     
     
         16 . The method of  claim 13  further comprising the step of adjusting said threshold water pressure of at least one of said plurality of valves by adjusting a tension on the biasing mechanism of said at least one valve. 
     
     
         17 . The method of  claim 13  further comprising the steps of removing and replacing the biasing members on each valve in order to adjust the threshold water pressure needed to activate each valve. 
     
     
         18 . The method of  claim 13  wherein said housing parts comprise complementary threadings, and comprising the additional step of unthreading the first and second housing parts to increase the length of the chamber in order to reduce the threshold water pressure needed to separate the piston from the stop of each valve. 
     
     
         19 . The method of  claim 13  wherein said housing parts comprise complementary threadings, and comprising the additional step of threading the first and second housing parts together to decrease the length of the chamber in order to increase the threshold water pressure needed to separate the piston from the stop of each valve. 
     
     
         20 . The method of  claim 13  wherein the threshold water pressure is less than the pressure needed to fully operate each of said plurality of emission devices.